Seasonal dynamics of population of the feather mite Monojoubertia microphylla (Astigmata: Analgoidea: Proctophyllodidae) in the chaffinch Fringilla coelebs

The seasonal dynamics of the Monojoubertia microphylla micropopulations in different sex and age groups of the chaffinch Fringilla coelebs (Passeriformes: Fringillidae) have been studied during the nest and migration periods in the North-West of Russia. Three bird groups were determined within the chaffinch population during the study: adult males, adult females, immature chaffinches. Total number of bird specimens examined--353. In all chaffinch groups, the mean mite numbers and age structure of mite micropopulations were similar during the spring migration. The number of mites gradually increased from April to May. During the nest and autumn migration periods the seasonal dynamics of M. microphylla micropopulations were quite different on adult males and females of the chaffinch, because of different roles of male and female in the process of infestation the young bird generation. On the adult chaffinch males, the mite number continued to increase during the breeding period (June) and began to decrease significantly in July because of the postbreeding plumage moult. The mite number slowly decreased in the end of summer and the autumn migration. On the adult chaffinch females, the mite number decreased abruptly during the nest period. During this period, the chaffinch female sits together with nestlings for a long time, and the great number of its mites (about 60% of mite micropopulation) moves from the female onto the nestlings. The mite micropopulation migrated onto nestling is represented mainly by males, females (about 25% each) and tritonymphs (38%). Total mite number on the chaffinch females continued to decrease in July under the influence of postbreeding moult and slightly increased up to the autumn migration only. On the young chaffinches, the number of M. microphylla quickly increased during the second part of summer. It is the result of the great quota of mite instars being ready for the reproduction (imago, tritonymphs) within the micropopulation migrated from the chaffinch female onto the nestlings. The decrease of the M. microphylla micropopulation on the young birds was observed in the autumn only. In the end autumn migration (October), the mean numbers of mites on all chaffinch groups became approximately similar, but did not reach the mean rate observed in the beginning of the spring migration. During both migration periods, the imago and all preimaginal instars of M. microphylla were active, the diapause was not observed. In the beginning of spring migration and the end of autumn migration the main part of the mite micropopulations was represented by females, while in all other periods of chaffinch's stay in the North-West of Russia the immature instars predominated.     

家蝇巨螯螨的侵袭行为及其对蝇类的影响

本文报道1983年4月至1984年9月对家蝇巨螯螨的某些行为的观察研究结果,包括对跗节1形态的扫描电镜观察,以及截肢前后侵袭家蝇的行为。见到跗节1有约10根毛状感受器,它们在感觉和寻找宿主上起重要作用。该螨对腐食性蝇类,如家蝇、厩腐蝇、夏厕蝇等具有较强的侵袭力。该螨在附着蝇体当螨量超过10只时,宿主卵巢滤泡发育受抑制,寿命缩短。每只雌螨每天平均消耗2个蝇卵,每4只雌螨每天平均消耗1条1龄蝇类幼虫。另外,也观察到家蝇成虫的日龄与性别对螨的诱引力没有明显差异,而卵的新鲜程度却有明显的差异。最后,对实验结果加以讨论,并对该螨的研究和利用提出一些建议。     

Ultrafine structure of salivary glands of the chicken mite Dermanyssus gallinae (Acarina, Gamasina, Dermanyssidae)

Using the method of transmission electron microscopy, structure of salivary glands of the chicken mite Dermanyssus gallinae (De Geer, 1778) is studied. Structure of the glands and of their ducts is described. The cellular composition, ultrastructural characteristics of secretion, and peculiarities of its release from cells are revealed.     

A qualitative model of mortality in honey bee (<Emphasis Type="Italic">Apis mellifera</Emphasis>) colonies infested with tracheal mites (<Emphasis Type="Italic">Acarapis woodi</Emphasis>)

The tracheal mite has been associated with colony deaths worldwide since the mite was first discovered in 1919. Yet controversy about its role in honey bee colony mortality has existed since that time. Other pathogens such as bacteria and viruses have been suggested as the cause of colony deaths as well as degenerative changes in individual honey bees. Using data from published work we developed a qualitative mortality model to explain colony mortality due to tracheal mite infestation in the field. Our model suggests that colonies of tracheal-mite infested honey bees, with no other pathogens present, can die out in the late winter/early spring period due to their inability to thermoregulate. An accumulation of factors conspire to cause colony death including reduced brood/bee population, loose winter clusters, reduced flight muscle function and increasing mite infestation. In essence a cascade effect results in the colony losing its cohesion and leading to its ultimate collapse.     

Studies on the development biology of Tropilaelaps clareae Delfinado and Baker (Acarina: Laelapidae) vis a vis the threshold stage in the life cycle of Apis mellifera Linn. (Hymenoptera: Apidae).

The biology of the parasitic mite Tropilaelaps clareae Delfinado and Baker (Acarina: Laelapidae) was studied with a view to identify the time of invasion of the mite into the honey bee (Apis mellifera) brood and the threshold stage in the life cycle of the host. Honey bee brood was sequentially sampled on day 0, 4, 8, 12, 16 and 20 of development. Adult T. clareae infested the 8-day larva shortly before its cell was capped. The larvac, protonymphs, deutonymphs and adults of T. clareae were all found parasitising bright red eyed pupae during day 16 of brood development. This was identified as the most parasitised stage in the life cycle of the host. The mite developed from egg to adult in about 8 days.     

An ultrastructural study of the relationship between the mite Floracarus perrepae Knihinicki & Boczek (Acariformes: Eriophyidae) and the fern Lygodium microphyllum (Lygodiaceae)

Abstract  The ultrastructure of the mite Floracarus perrepae was investigated in relation to its host, Lygodium microphyllum , the Old World climbing fern. Floracarus perrepae has been suggested as a means of biological control for the fern, which is an aggressive weed in tropical areas. Feeding by the mite induces a change in the size of epidermal cells, and cell division is stimulated by mite feeding, causing the leaf margin to curl over into a roll with two to three windings. The enlarged epidermal layer greatly increases its cytoplasmic contents, which become a nutritive tissue for the mite and its progeny. Damage by the mite ultimately debilitates the fern. The structure and depth of stylet penetration by the mite, and the thickness of the epidermal cell wall of L. microphyllum , do not appear to account for the mite's differential ability to induce leaf rolling in its co-adapted host from south-east Queensland but not in the invasive genotype of the fern in Florida.     

Ultrastructure of salivary glands of the chicken red mite <Emphasis Type="Italic">Dermanyssus gallinae</Emphasis> (Acarina,Gamasina, Dermanyssidae)

Structure of salivary glands of the chicken red mite, Dermanyssus gallinae (De Geer, 1778) was studied using transmission electron microscopy. Structure of the glands and their ducts is described. The cell composition, ultrastructural characteristics of the secretion, and peculiarities of its release from cell are revealed.     

Influence of young potted apple tree water status on European Red Mite (Acari: Tetranychidae) abundance

The effect of water-stress on population growth of the European Red Mite (ERM) Panonychus ulmi (Koch) was tested in a plastic shelter using young potted apple trees under three water treatment. Mite abundance was significantly greater with higher water supply. The relationship between plant water status and mite number was non-linear, both treatments with leaf water potential from-30 to about -5 bars bearing the lower mite populations. Over the threshold value of-5 bars, mite number sharply increased four times. A non-linear regression analysis showed that the stomatal conductance explained 49.7% of the variance in mite number. Low leaf surface humidity resulting from reduced leaf transpiration of water-stressed trees may increase mite egg and larval mortalities. Daily leaf surface temperatures on the water-stressed trees averaged 1.5°C higher than on the other trees, but did not result in an increase in mite populations, because of the negative influence of low leaf humidity.     

SARCOMERE SIZE IN DEVELOPING MUSCLES OF A TARSONEMID MITE

The embryo of a tarsonemid mite was found to be suitable for in vivo observations of muscle development by polarization microscopy. The four dorsal muscles of the metapodosoma each contain three sarcomeres, the anterior two of which can be seen clearly. These sarcomeres can be identified and followed during much of their development. Sarcomeres are about 2.5 micra long when first detected and increase in length until they are about 10 micra long. The change in length is associated with a slow, approximately constant rate of increase in the length of the A region, and an initially slow then much more rapid increase in the length of the I band. Preceding the period when the I band elongates rapidly there is an increase in the diameter of the muscle fibers and an increase in the retardation of the A band. A, I, Z, and H bands are visible during most of these changes. The change in A band length has been interpreted in terms of the growth of the A filaments which have been observed by electron microscopy in muscles of other animals. It is suggested that the exceptionally long sarcomeres in this mite result from the early fixing of the number of sarcomeres in a given muscle fiber.     

Abundance and temporal distribution of Ornithonyssus sylviarum Canestrini and Fanzago (Acarina: Mesostigmata) in gray catbird (Dumatella carolinensis) nests.

The northern fowl mite, Ornithonyssus sylviarum Canestrini and Fanzago, is a common ectoparasite of wild birds. Despite its ability to transmit eastern equine encephalitis (EEE) virus under laboratory conditions and potential for involvement in the natural EEE virus cycle, we know little about its abundance or temporal distribution in nature. From June to August 2000, we studied the abundance of O. sylviarum in the nests of gray catbirds (Dumatella carolinensis), a reservoir host for EEE virus, at Killbuck Marsh Wildlife Area (KMWA), a known EEE virus focus in Wayne County, Ohio. A total of 7,883 O. sylviarum, including 1,910 adults and 5,973 protonymphs, were recovered from 23 of 26 gray catbird nests collected during various phases of the nesting cycle. We found no association between mite abundance and number of catbird nestlings in successful nests. However, mite abundance increased significantly with date of nest collection and peaked in late July when transmission of EEE virus is likely to occur at KMWA. We therefore suggest that O. sylviarum may contribute to the transmission of EEE virus among gray catbirds at KMWA.     

The attachment and stylostome of Trombidium newelli (Acari: Trombidiidae), an ectoparasitic mite on adults of alfalfa weevil, Hypera postica (Coleoptera: Curculionidae)

Larvae of the mite Trombidium newelli Welbourn and Flessel are ectoparasitic on adult alfalfa weevil, Hypera postica (Gyllenhall), an insect pest of alfalfa. The mite larvae are found under the elytra, attached to the dorsal surface of weevils abdomen. T. newelli larvae use their chelicerae to penetrate the pliable and weakly sclerotized areas of the hosts integument, and to hold on firmly to the host. The attachment sites associated with larval mites of different degrees of engorgement were examined using both light and scanning electron microscopy. The ventral inside surface of parasitized host tergites revealed a characteristic injury as spots varying in color from white-yellow to golden-brown depending on the engorged size of the mite. In addition, spots associated with fully engorged mite larvae showed an aggressive dendritically radiating mass expanding outward from the site of cheliceral penetration. This mass, known as feeding tube or stylostome was branched, with each branch ending in a cluster of closed bulbs. Stylostomes appear to exist independently in the hosts tissue. Stylostome mass corresponded with the engorgement state of the mite, increasing as the mite larva increased in size. The possible nature and mechanism of stylostome formation is discussed.     

咸宁地区桔全爪螨与天敌种群动态的初步研究

咸宁地区桔全爪螨与天敌种群动态的初步研究甘宗义,王盛桃（湖北省农科院果树茶叶研究所,武昌４３０２０９）ＰｏｐｕｌａｔｉｏｎＤｙｎａｍｉｃｓｏｆＣｉｔｒｕｓＲｃｄＭｉｔｅ（ＰａｎｏｎｙｃｈｕｓｃｉｔｒｉＭｃＧ．）ａｎｄＩｔｓＮａｔｕｒａｌＥｎｅｍｉｅｓ...     

Complete sequence analysis of 18S rDNA based on genomic DNA extraction from individual Demodex mites (Acari: Demodicidae)

The study for the first time attempted to accomplish 18S ribosomal DNA (rDNA) complete sequence amplification and analysis for three Demodex species (Demodex folliculorum, Demodex brevis and Demodex canis) based on gDNA extraction from individual mites. The mites were treated by DNA Release Additive and Hot Start II DNA Polymerase so as to promote mite disruption and increase PCR specificity. Determination of D. folliculorum gDNA showed that the gDNA yield reached the highest at 1 mite, tending to descend with the increase of mite number. The individual mite gDNA was successfully used for 18S rDNA fragment (about 900 bp) amplification examination. The alignments of 18S rDNA complete sequences of individual mite samples and those of pooled mite samples ( ≥ 1000mites/sample) showed over 97% identities for each species, indicating that the gDNA extracted from a single individual mite was as satisfactory as that from pooled mites for PCR amplification. Further pairwise sequence analyses showed that average divergence, genetic distance, transition/transversion or phylogenetic tree could not effectively identify the three Demodex species, largely due to the differentiation in the D. canis isolates. It can be concluded that the individual Demodex mite gDNA can satisfy the molecular study of Demodex. 18S rDNA complete sequence is suitable for interfamily identification in Cheyletoidea, but whether it is suitable for intrafamily identification cannot be confirmed until the ascertainment of the types of Demodex mites parasitizing in dogs.     

AN ORIBATID MITE (ARACHNIDA: ACARI) FROM THE OXFORD CLAY (JURASSIC: UPPER CALLOVIAN) OF SOUTH CAVE STATION QUARRY, YORKSHIRE, UK

Abstract:  A single specimen of a new species of oribatid mite belonging to the genus Jureremus Krivolutsky, in Krivolutsky and Krassilov 1977 , previously described from the Upper Jurassic of the Russian Far East, is described as J. phippsi sp. nov. The mite is preserved by iron pyrite replacement, and was recovered by sieving from the Oxford Clay Formation (Jurassic: Upper Callovian) of South Cave, Yorkshire. It is the first record of a pre-Pleistocene mite, and the second species record of the family Cymbaeremaeidae, from the British Isles; also, it is only the third record of Acari from the Jurassic Period. The presence of a terrestrial mite in a sedimentary sequence of open marine origin is noteworthy, and suggestions for its mode of transport to the site of deposition are discussed.     

Phylogenetic investigation of the genus Raoiella (Prostigmata: Tenuipalpidae): diversity, distribution, and world invasions

The genus Raoiella is best known because of the red palm mite, R. indica, a major pest of palms spreading aggressively throughout the Americas. Not much was known about the biology, geographic origins, or evolutionary history of the genus when R. indica emerged as a major invasive pest. This paper attempts to address some of the basic historical questions regarding the palm mite as well as the genus. Molecular characters from COI and 28S regions were used to produce a phylogenetic hypothesis for the genus in an effort to understand its geographic origin. It also uses COI barcode data to delimit several potentially new species discovered by the authors in Australia. Results show a basal split between R. indica and all other Raoiella species, which indicates Africa or the Middle East as the most probable origin of the genus. Additionally, COI data suggests that at least eight new species are represented among the 20 Australian populations included in this study.     

Rainforest habitat resistance to the migration of Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) in south-eastern Queensland

Abstract  This paper tests the hypothesis that habitat differences affect the migratory ability of the Chilean predatory mite, Phytoseiulus persimilis , an introduced biological control agent of the spider mite, Tetranychus urticae . It is suggested that habitat resistance accounts for the species' inability to invade rainforests in south-eastern Queensland, Australia. Like its prey, P. persimilis migrates to distant plants on air currents. To test our hypothesis, populations of the Chilean predatory mite were established on potted bean plants in both remnant rainforest and adjacent open fields, and their migration monitored using sticky traps. Overall it was found that prey populations on leaves were similar in both habitats, but those of predators were about 20% lower in rainforest. However, the numbers of both predators and prey caught on sticky traps in rainforest were about 6% and 25%, respectively, of those caught in open fields, indicating a strongly reduced rate of aerial migration in the forest. The number of P. persimilis caught on the sticky traps increased with increasing populations of predators on foliage. Thus, dense vegetation inhibits the movement of air currents and inhibits colonisation by both predators and, to a lesser extent, spider mites. These results suggest that the inhibition of aerial migration is one reason for lower numbers of P. persimilis in forest habitats, both because its own vagility is restricted, and because its prey is less able to disperse.     

A new fungal pathogen of the scavenger mite,Tydeus gloveri

A new fungal pathogen, Hirsutella tydeicola, was found causing epizootics in populations of the scavenger mite, Tydeus gloveri, during the summer of 1979 and 1980 on citrus in Florida. The fungus is described in association with its host using light and scanning electron microscopy. H. tydeicola is compared with a closely related species, H. thompsonii, a coexisting pathogen of the citrus rust mite. All attempts to isolate the fungus on various agar media failed.     

Mite‐y bees: bumble bees (Bombus spp., Hymenoptera: Apidae) host a relatively homogeneous mite (Acari) community,shaped by bee species identity but not by geographic proximity

1. Parasites can affect the communities of their hosts; and hosts, in turn, shape communities of parasites and other symbionts. This makes host–symbiont relationships a key but often overlooked aspect of community ecology. 2. Mites associated with bees have a range of lifestyles; however, little is known about mites associated with wild bees or about factors influencing the make‐up of bee‐associated mite communities. This study investigated how mite communities associated with bumble bees (Bombus spp.) are shaped by the Bombus community and geographic proximity. 3. Bees were collected from 15 sites in Ontario, Canada, and examined for mites. Mite abundance and species richness increased with local bee abundance. Several bee species also differed in mite abundance, species richness, prevalence, and diversity. Locally uncommon species tended to have more mites than other bees. Queen bees had the most mites, and males had more mites than workers. 4. Spatial proximity was not a predictor of mite community composition, despite a strong effect of proximity on bee community similarity. 5. On the 11 Bombus spp. examined, 33 mite species were found. Whereas nearly half of these mite species are obligate associates of bumble bees, none was restricted to particular Bombus species. 6. The best predictor of mite community composition was bee identity. Although many parasite communities show strong geographic patterns, the communities of primarily commensalistic bee‐mites in this study did not. These findings have implications for bumble bee conservation, given that pollen‐feeding commensals might become harmful at high densities or act as disease vectors.     

The ecology, morphology and behaviour of Bakerdania elliptica (Acari: Prostigmata: Pygmephoridae), a mite associated with terrestrial isopods

In deciduous woodlands near to Bristol, South-west England, about one in ten specimens of the woodlouse Oniscus asellus (L.) are infested with Bakerdania elliptica (Krczal, 1959), a small pygmephorid mite of about 200 pm in length. Woodlice in the field rarely carry more than three mites, which are usually attached to the mid or lateral regions of the sixth and seventh pereonites on the ventral surface of the isopod. These 'favoured sites' correspond to regions of the exoskeleton of the woodlouse which are free from abrasion as they move through leaf litter. Mites removed from these areas and replaced on the first pereonite return to a favoured site, usually within 30 min. During this process they exhibit four distinct types of behaviour.]
Uninfested specimens of Oniscus usellus maintained in laboratory tanks on leaf litter from their 'own' site all become infested with mites within a week. The number of mites on the isopods increases rapidly under these conditions. After six weeks, each individual carries a mean of about 50 mites. The level of infestation is subsequently stable, probably due to saturation of favoured sites, since large numbers of unattached mites can be found in the leaf litter during this period.
Studies by light microscopy and scanning electron microscopy have shown that Bakerdania elliptica does not feed while attached to the cuticle of Oniscus asellus , and that all attached mites are females. Males are extremely rare and occur only in leaf litter. These observations suggest that the relationship between Bakerdania elliptica and Oniscus asellus is one of phoresy and that female mites use woodlice as an aid to dispersal during their life cycle.     

Spatio-temporal population genetic structure of the parasitic mite Spinturnix bechsteini is shaped by its own demography and the social system of its bat host

Information about the population genetic structures of parasites is important for an understanding of parasite transmission pathways and ultimately the co-evolution with their hosts. If parasites cannot disperse independently of their hosts, a parasite's population structure will depend upon the host's spatial distribution. Geographical barriers affecting host dispersal can therefore lead to structured parasite populations. However, how the host's social system affects the genetic structure of parasite populations is largely unknown. We used mitochondrial DNA (mtDNA) to describe the spatio-temporal population structure of a contact-transmitted parasitic wing mite ( Spinturnix bechsteini ) and compared it to that of its social host, the Bechstein's bat ( Myotis bechsteinii ). We observed no genetic differentiation between mites living on different bats within a colony. This suggests that mites can move freely among bats of the same colony. As expected in case of restricted inter-colony dispersal, we observed a strong genetic differentiation of mites among demographically isolated bat colonies. In contrast, we found a strong genetic turnover between years when we investigated the temporal variation of mite haplotypes within colonies. This can be explained with mite dispersal occuring between colonies and bottlenecks of mite populations within colonies. The observed absence of isolation by distance could be the result from genetic drift and/or from mites dispersing even between remote bat colonies, whose members may meet at mating sites in autumn or in hibernacula in winter. Our data show that the population structure of this parasitic wing mite is influenced by its own demography and the peculiar social system of its bat host.